//输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字。 
//
// 
//
// 示例 1： 
//
// 输入：matrix = [[1,2,3],[4,5,6],[7,8,9]]
//输出：[1,2,3,6,9,8,7,4,5]
// 
//
// 示例 2： 
//
// 输入：matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
//输出：[1,2,3,4,8,12,11,10,9,5,6,7]
// 
//
// 
//
// 限制： 
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// 
// 0 <= matrix.length <= 100 
// 0 <= matrix[i].length <= 100 
// 
//
// 注意：本题与主站 54 题相同：https://leetcode-cn.com/problems/spiral-matrix/ 
//
// Related Topics 数组 矩阵 模拟 👍 563 👎 0


package leetcode.editor.cn;

class 顺时针打印矩阵 {
    public static void main(String[] args) {
        Solution solution = new 顺时针打印矩阵().new Solution();
        // TO TEST
    }

    //leetcode submit region begin(Prohibit modification and deletion)
    class Solution {
        public int[] spiralOrder1(int[][] matrix) {
            if (matrix == null || matrix.length == 0 || matrix[0].length == 0) return new int[0];
            int rows = matrix.length, columns = matrix[0].length;
            int left = 0, right = columns - 1, top = 0, bottom = rows - 1;
            int[] order = new int[rows * columns];
            int index = 0;
            while (left <= right && top <= bottom) {
                for (int i = left; i <= right; i++) {
                    order[index++] = matrix[top][i];
                }
                for (int i = top + 1; i <= bottom; i++) {
                    order[index++] = matrix[i][right];
                }

                if (left < right && top < bottom) {
                    for (int i = right - 1; i > left; i--) {
                        order[index++] = matrix[bottom][i];
                    }
                    for (int i = bottom; i > top; i--) {
                        order[index++] = matrix[i][left];
                    }
                }
                left++;
                right--;
                top++;
                bottom--;
            }
            return order;
        }

        /**
         * 头脑风暴法（纯沙伯
         * @param matrix
         * @return
         */
        public int[] spiralOrder2(int[][] matrix) {
            if (matrix == null || matrix.length == 0 || matrix[0].length == 0) return new int[0];
            int[][] directions = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
            int rows = matrix.length, columns = matrix[0].length;
            int row = 0, column = 0;
            int index = 0;
            int left = 0, right = matrix[0].length - 1, top = 0, bottom = matrix.length - 1;
            int[] order = new int[rows * columns];
            int times = 0;
            while (left <= right && top <= bottom) {
                order[times++] = matrix[row][column];
                int nextRow = row + directions[index][0], nextColum = column + directions[index][1];
                if (nextColum > right || nextColum < left || nextRow > bottom || nextRow < top) {
                    index = (index + 1) % 4;
                    if (nextColum > right) top++;
                    else if (nextRow > bottom) right--;
                    else if (nextColum < left) bottom--;
                    else if (nextRow < top) left++;
                }
                row = row + directions[index][0];
                column = column + directions[index][1];
            }
            return order;
        }

        public int[] spiralOrder(int[][] matrix) {
            if (matrix == null || matrix.length == 0 || matrix[0].length == 0) return new int[0];
            int[][] directions = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
            int rows = matrix.length, columns = matrix[0].length;
            int row = 0, column = 0;
            int total = rows * columns;
            int index = 0;
            boolean[][] visited = new boolean[rows][columns];
            int[] order = new int[total];
            for (int i = 0; i < total; i++) {
                order[i] = matrix[row][column];
                visited[row][column] = true;
                int nextRow = row + directions[index][0], nextColum = column + directions[index][1];
                if (nextColum >= columns || nextColum < 0 || nextRow >= rows || nextRow < 0 || visited[nextRow][nextColum]) {
                    index = (index + 1) % 4;
                }
                row = row + directions[index][0];
                column = column + directions[index][1];
            }
            return order;
        }
    }
//leetcode submit region end(Prohibit modification and deletion)

}

